帮忙做一个关于无序列表的问题

import java.util.*;
public class testhaidao
{
static int m = 0;//定义下朋友的号码
    public static void main(String args[]) {
        ArrayList<Integer> a = new ArrayList<Integer>();
        for (int i = 1; i <= 10; i++) {//10为你要输入的旅游的人数，
            a.add(i);
        }
        while (a.size() >1) {
            for (int i = 0; i < a.size(); i++) {
                m++;
                if (m % 3 == 0) {//当为3的时候就删除
                    m = 0;//删除的这个小朋友看作是0
                    a.remove(i);//执行删除
    System.out.println((i+1)+"死了");
                    i--;//删除一个之后将这个小朋友的号码去掉
                }
            }
        }
        System.out.println("你应该站在旅游团的: " + a.get(0)+"位");
    }
}

import java.util.ArrayList;
import java.util.Scanner;

public class B_H_J {
    private ArrayList<Person> persons = new ArrayList<Person>();

    public B_H_J() {

    }

    private void init(int n) {
        persons.clear();
        for (int i = 1; i <= n; i++) {
            persons.add(new Person(i));
        }
    }

    private boolean has7(int num) {
        while (num > 0) {
            if (num % 10 == 7)
                return true;
            else
                num = num / 10;
        }
        return false;
    }

    public void execute(int n) {
        try {
            if (n < 10)
                throw new Exception();
        } catch (Exception e) {
            e.printStackTrace();
        }
        init(n);
        boolean direct = true;// 正序为true,反序为false;
        int i = 1;
        int current = 0;
        while (persons.size() > 1) {
            current = (current + persons.size()) % persons.size();//将current转换为合法的索引值
            System.out.println("person " + persons.get(current).getId() + "数数，数为:" + i);
            if (i % 7 == 0 || has7(i)) {
                System.out.println("person " + persons.get(current).getId() + "行酒令，并退出圈子");
                persons.remove(current);
                direct = !direct;
                if (!direct)
                    current -= 1;
            } else {
                if (direct)
                    current += 1;
                else
                    current -= 1;
            }
            i++;
        }
    }

    public static void main(String args[]) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        B_H_J test = new B_H_J();
        test.execute(n);
    }
}

class Person {
    private int id;

    public Person(int id) {
        this.id = id;
    }

    public int getId() {
        return this.id;
    }
}